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10-petal western star, evening starflower, gumbo-lily, tenpetal blazingstar

gold blazingstar, golden blazingstar

Habit Plants biennial or perennial, bushlike, perennials with ground-level caudices. Plants biennial, bushlike or candelabra-form.
Stems

solitary, erect, straight;

branches distal or along entire stem, proximal or distal longest, antrorse, straight to upcurved; hairy.

solitary, erect, straight;

branches distal or along entire stem, distal or proximal longest, antrorse, straight; hairy.

Leaves

blade 72–295 × 14–45 mm, widest intersinus distance 10.1–23.3 mm;

proximal oblanceolate or elliptic, margins serrate to pinnate, teeth or lobes 16–26, slightly antrorse, 1–16.5 mm;

distal elliptic to lanceolate, base clasping or not, margins serrate to pinnate, teeth or lobes 9–20, slightly antrorse, 5.3–13.7 mm;

surfaces with needlelike trichomes.

blade 38–113 × 8–20.5(–25.2) mm, widest intersinus distance 5.4–12.8 mm;

proximal oblanceolate, lanceolate, or elliptic, margins serrate to pinnate, teeth or lobes 14–22, slightly antrorse, 0.6–4.6 mm;

distal elliptic or lanceolate, base not clasping, margins serrate to pinnate, teeth or lobes 6–22, slightly antrorse, 0.6–4 mm;

abaxial surface with simple grappling-hook, complex grappling-hook, and needlelike trichomes, adaxial surface with simple grappling-hook and needlelike trichomes.

Bracts

margins pinnate.

margins toothed.

Flowers

petals white, 47–75 × 13–22.7 mm, apex acute to attenuate, glabrous abaxially;

stamens white to yellow, 5 outermost petaloid, filaments spatulate, strongly clawed, 48–75 × 12–23 mm, without anthers, second whorl with anthers;

anthers straight after dehiscence, epidermis smooth;

styles 36–53 mm.

petals light to golden yellow, 12.5–21.4 × 3.8–6.7 mm, apex acute to rounded, glabrous abaxially;

stamens light to golden yellow, 5 outermost petaloid, filaments narrowly spatulate, slightly clawed, 11.5–18.6 × 2–5.8 mm, without anthers, second whorl with anthers;

anthers straight after dehiscence, epidermis smooth;

styles 8.1–13.1 mm.

Capsules

cylindric, 30–43 × 12–17 mm, base tapering, not longitudinally ridged.

cup-shaped to cylindric, 9.4–16 × 5.1–7.7 mm, base tapering, not longitudinally ridged.

Seeds

2.3–4 mm;

coat anticlinal cell walls straight, papillae 4–10 per cell.

coat anticlinal cell walls sinuous, papillae 29–35 per cell.

2n

= 22.

= 20.

Mentzelia decapetala

Mentzelia chrysantha

Phenology Flowering Jun–Aug(–Oct). Flowering Jul–Sep.
Habitat Rock outcrops, slopes, dry short-grass prairies, riverbanks, roadsides, loam, limestone, sandy, silty, clayey, and gravelly soils. Steep hillsides, washes, clayey soils, sometimes rich in gypsum.
Elevation 300–2400 m. (1000–7900 ft.) 1600–1900 m. (5200–6200 ft.)
Distribution
from FNA
CO; IA; IL; KS; MN; MT; NE; NM; OK; SD; TX; UT; WY; AB; MB; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
CO
[BONAP county map]
Discussion

Mentzelia decapetala is introduced in Grundy County, Illinois. It appears to be native throughout the rest of its distribution.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Mentzelia chrysantha occurs in Custer and Fremont counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 12, p. 504. FNA vol. 12, p. 523.
Parent taxa Loasaceae > Mentzelia > sect. Bartonia Loasaceae > Mentzelia > sect. Bartonia
Sibling taxa
M. affinis, M. albescens, M. albicaulis, M. argillicola, M. argillosa, M. aspera, M. asperula, M. candelariae, M. canyonensis, M. chrysantha, M. collomiae, M. congesta, M. conspicua, M. crocea, M. cronquistii, M. densa, M. desertorum, M. dispersa, M. eremophila, M. filifolia, M. floridana, M. flumensevera, M. goodrichii, M. gracilenta, M. hirsutissima, M. holmgreniorum, M. hualapaiensis, M. humilis, M. integra, M. involucrata, M. inyoensis, M. isolata, M. jonesii, M. laciniata, M. laevicaulis, M. lagarosa, M. leucophylla, M. librina, M. lindheimeri, M. lindleyi, M. longiloba, M. marginata, M. memorabilis, M. mexicana, M. micrantha, M. mollis, M. monoensis, M. montana, M. multicaulis, M. multiflora, M. nitens, M. nuda, M. obscura, M. oligosperma, M. oreophila, M. pachyrhiza, M. packardiae, M. paradoxensis, M. pectinata, M. perennis, M. polita, M. procera, M. pterosperma, M. puberula, M. pumila, M. ravenii, M. reflexa, M. reverchonii, M. rhizomata, M. rusbyi, M. saxicola, M. shultziorum, M. sivinskii, M. speciosa, M. springeri, M. strictissima, M. thompsonii, M. tiehmii, M. todiltoensis, M. torreyi, M. tricuspis, M. tridentata, M. uintahensis, M. veatchiana
M. affinis, M. albescens, M. albicaulis, M. argillicola, M. argillosa, M. aspera, M. asperula, M. candelariae, M. canyonensis, M. collomiae, M. congesta, M. conspicua, M. crocea, M. cronquistii, M. decapetala, M. densa, M. desertorum, M. dispersa, M. eremophila, M. filifolia, M. floridana, M. flumensevera, M. goodrichii, M. gracilenta, M. hirsutissima, M. holmgreniorum, M. hualapaiensis, M. humilis, M. integra, M. involucrata, M. inyoensis, M. isolata, M. jonesii, M. laciniata, M. laevicaulis, M. lagarosa, M. leucophylla, M. librina, M. lindheimeri, M. lindleyi, M. longiloba, M. marginata, M. memorabilis, M. mexicana, M. micrantha, M. mollis, M. monoensis, M. montana, M. multicaulis, M. multiflora, M. nitens, M. nuda, M. obscura, M. oligosperma, M. oreophila, M. pachyrhiza, M. packardiae, M. paradoxensis, M. pectinata, M. perennis, M. polita, M. procera, M. pterosperma, M. puberula, M. pumila, M. ravenii, M. reflexa, M. reverchonii, M. rhizomata, M. rusbyi, M. saxicola, M. shultziorum, M. sivinskii, M. speciosa, M. springeri, M. strictissima, M. thompsonii, M. tiehmii, M. todiltoensis, M. torreyi, M. tricuspis, M. tridentata, M. uintahensis, M. veatchiana
Synonyms Bartonia decapetala Nuttallia chrysantha
Name authority (Pursh) Urban: Ber. Deutsch. Bot. Ges. 10: 263. (1892) Engelmann: Bull. U.S. Geol. Geogr. Surv. Territ. 2: 237. (1876)
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